arch/score/kernel/signal.c - arm/linux-arm64-legacy - Git at Google

 /*
  * arch/score/kernel/signal.c
  *
  * Score Processor version.
  *
  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
  *  Chen Liqin <liqin.chen@sunplusct.com>
  *  Lennox Wu <lennox.wu@sunplusct.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see the file COPYING, or write
  * to the Free Software Foundation, Inc.,
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #include <linux/errno.h>
 #include <linux/signal.h>
 #include <linux/unistd.h>
 #include <linux/uaccess.h>

 #include <asm/syscalls.h>
 #include <asm/ucontext.h>

 #include <asm/cacheflush.h>

 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

 struct rt_sigframe {
 	u32 rs_ass[4];		/* argument save space */
 	u32 rs_code[2];		/* signal trampoline */
 	struct siginfo rs_info;
 	struct ucontext rs_uc;
 };

 static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	int err = 0;
 	unsigned long reg;

 	reg = regs->cp0_epc; err |= __put_user(reg, &sc->sc_pc);
 	err |= __put_user(regs->cp0_psr, &sc->sc_psr);
 	err |= __put_user(regs->cp0_condition, &sc->sc_condition);


 #define save_gp_reg(i) {				\
 	reg = regs->regs[i];				\
 	err |= __put_user(reg, &sc->sc_regs[i]);	\
 } while (0)
 	save_gp_reg(0); save_gp_reg(1); save_gp_reg(2);
 	save_gp_reg(3); save_gp_reg(4); save_gp_reg(5);
 	save_gp_reg(6);	save_gp_reg(7); save_gp_reg(8);
 	save_gp_reg(9); save_gp_reg(10); save_gp_reg(11);
 	save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
 	save_gp_reg(15); save_gp_reg(16); save_gp_reg(17);
 	save_gp_reg(18); save_gp_reg(19); save_gp_reg(20);
 	save_gp_reg(21); save_gp_reg(22); save_gp_reg(23);
 	save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
 	save_gp_reg(27); save_gp_reg(28); save_gp_reg(29);
 #undef save_gp_reg

 	reg = regs->ceh; err |= __put_user(reg, &sc->sc_mdceh);
 	reg = regs->cel; err |= __put_user(reg, &sc->sc_mdcel);
 	err |= __put_user(regs->cp0_ecr, &sc->sc_ecr);
 	err |= __put_user(regs->cp0_ema, &sc->sc_ema);

 	return err;
 }

 static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	int err = 0;
 	u32 reg;

 	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
 	err |= __get_user(regs->cp0_condition, &sc->sc_condition);

 	err |= __get_user(reg, &sc->sc_mdceh);
 	regs->ceh = (int) reg;
 	err |= __get_user(reg, &sc->sc_mdcel);
 	regs->cel = (int) reg;

 	err |= __get_user(reg, &sc->sc_psr);
 	regs->cp0_psr = (int) reg;
 	err |= __get_user(reg, &sc->sc_ecr);
 	regs->cp0_ecr = (int) reg;
 	err |= __get_user(reg, &sc->sc_ema);
 	regs->cp0_ema = (int) reg;

 #define restore_gp_reg(i) do {				\
 	err |= __get_user(reg, &sc->sc_regs[i]);	\
 	regs->regs[i] = reg;				\
 } while (0)
 	restore_gp_reg(0); restore_gp_reg(1); restore_gp_reg(2);
 	restore_gp_reg(3); restore_gp_reg(4); restore_gp_reg(5);
 	restore_gp_reg(6); restore_gp_reg(7); restore_gp_reg(8);
 	restore_gp_reg(9); restore_gp_reg(10); restore_gp_reg(11);
 	restore_gp_reg(12); restore_gp_reg(13); restore_gp_reg(14);
 	restore_gp_reg(15); restore_gp_reg(16); restore_gp_reg(17);
 	restore_gp_reg(18); restore_gp_reg(19);	restore_gp_reg(20);
 	restore_gp_reg(21); restore_gp_reg(22); restore_gp_reg(23);
 	restore_gp_reg(24); restore_gp_reg(25); restore_gp_reg(26);
 	restore_gp_reg(27); restore_gp_reg(28); restore_gp_reg(29);
 #undef restore_gp_reg

 	return err;
 }

 /*
  * Determine which stack to use..
  */
 static void __user *get_sigframe(struct k_sigaction *ka,
 			struct pt_regs *regs, size_t frame_size)
 {
 	unsigned long sp;

 	/* Default to using normal stack */
 	sp = regs->regs[0];
 	sp -= 32;

 	/* This is the X/Open sanctioned signal stack switching.  */
 	if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp)))
 		sp = current->sas_ss_sp + current->sas_ss_size;

 	return (void __user*)((sp - frame_size) & ~7);
 }

 asmlinkage long
 score_sigaltstack(struct pt_regs *regs)
 {
 	const stack_t __user *uss = (const stack_t __user *) regs->regs[4];
 	stack_t __user *uoss = (stack_t __user *) regs->regs[5];
 	unsigned long usp = regs->regs[0];

 	return do_sigaltstack(uss, uoss, usp);
 }

 asmlinkage long
 score_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
 	sigset_t set;
 	stack_t st;
 	int sig;

 	frame = (struct rt_sigframe __user *) regs->regs[0];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 		goto badframe;
 	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
 		goto badframe;

 	sigdelsetmask(&set, ~_BLOCKABLE);
 	spin_lock_irq(&current->sighand->siglock);
 	current->blocked = set;
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);

 	sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 	if (sig < 0)
 		goto badframe;
 	else if (sig)
 		force_sig(sig, current);

 	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
 		goto badframe;

 	/* It is more difficult to avoid calling this function than to
 	   call it and ignore errors.  */
 	do_sigaltstack((stack_t __user *)&st, NULL, regs->regs[0]);

 	__asm__ __volatile__(
 		"mv\tr0, %0\n\t"
 		"la\tr8, syscall_exit\n\t"
 		"br\tr8\n\t"
 		: : "r" (regs) : "r8");

 badframe:
 	force_sig(SIGSEGV, current);

 	return 0;
 }

 static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 		int signr, sigset_t *set, siginfo_t *info)
 {
 	struct rt_sigframe __user *frame;
 	int err = 0;

 	frame = get_sigframe(ka, regs, sizeof(*frame));
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		goto give_sigsegv;

 	/*
 	 * Set up the return code ...
 	 *
 	 *         li      v0, __NR_rt_sigreturn
 	 *         syscall
 	 */
 	err |= __put_user(0x87788000 + __NR_rt_sigreturn*2,
 			frame->rs_code + 0);
 	err |= __put_user(0x80008002, frame->rs_code + 1);
 	flush_cache_sigtramp((unsigned long) frame->rs_code);

 	err |= copy_siginfo_to_user(&frame->rs_info, info);
 	err |= __put_user(0, &frame->rs_uc.uc_flags);
 	err |= __put_user(0, &frame->rs_uc.uc_link);
 	err |= __put_user((void __user *)current->sas_ss_sp,
 				&frame->rs_uc.uc_stack.ss_sp);
 	err |= __put_user(sas_ss_flags(regs->regs[0]),
 				&frame->rs_uc.uc_stack.ss_flags);
 	err |= __put_user(current->sas_ss_size,
 				&frame->rs_uc.uc_stack.ss_size);
 	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));

 	if (err)
 		goto give_sigsegv;

 	regs->regs[0] = (unsigned long) frame;
 	regs->regs[3] = (unsigned long) frame->rs_code;
 	regs->regs[4] = signr;
 	regs->regs[5] = (unsigned long) &frame->rs_info;
 	regs->regs[6] = (unsigned long) &frame->rs_uc;
 	regs->regs[29] = (unsigned long) ka->sa.sa_handler;
 	regs->cp0_epc = (unsigned long) ka->sa.sa_handler;

 	return 0;

 give_sigsegv:
 	if (signr == SIGSEGV)
 		ka->sa.sa_handler = SIG_DFL;
 	force_sig(SIGSEGV, current);
 	return -EFAULT;
 }

 static int handle_signal(unsigned long sig, siginfo_t *info,
 	struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
 {
 	int ret;

 	if (regs->is_syscall) {
 		switch (regs->regs[4]) {
 		case ERESTART_RESTARTBLOCK:
 		case ERESTARTNOHAND:
 			regs->regs[4] = EINTR;
 			break;
 		case ERESTARTSYS:
 			if (!(ka->sa.sa_flags & SA_RESTART)) {
 				regs->regs[4] = EINTR;
 				break;
 			}
 		case ERESTARTNOINTR:
 			regs->regs[4] = regs->orig_r4;
 			regs->regs[7] = regs->orig_r7;
 			regs->cp0_epc -= 8;
 		}

 		regs->is_syscall = 0;
 	}

 	/*
 	 * Set up the stack frame
 	 */
 	ret = setup_rt_frame(ka, regs, sig, oldset, info);

 	spin_lock_irq(&current->sighand->siglock);
 	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
 	if (!(ka->sa.sa_flags & SA_NODEFER))
 		sigaddset(&current->blocked, sig);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);

 	return ret;
 }

 static void do_signal(struct pt_regs *regs)
 {
 	struct k_sigaction ka;
 	sigset_t *oldset;
 	siginfo_t info;
 	int signr;

 	/*
 	 * We want the common case to go fast, which is why we may in certain
 	 * cases get here from kernel mode. Just return without doing anything
 	 * if so.
 	 */
 	if (!user_mode(regs))
 		return;

 	if (test_thread_flag(TIF_RESTORE_SIGMASK))
 		oldset = &current->saved_sigmask;
 	else
 		oldset = &current->blocked;

 	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 	if (signr > 0) {
 		/* Actually deliver the signal.  */
 		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
 			/*
 			 * A signal was successfully delivered; the saved
 			 * sigmask will have been stored in the signal frame,
 			 * and will be restored by sigreturn, so we can simply
 			 * clear the TIF_RESTORE_SIGMASK flag.
 			 */
 			if (test_thread_flag(TIF_RESTORE_SIGMASK))
 				clear_thread_flag(TIF_RESTORE_SIGMASK);
 		}

 		return;
 	}

 	if (regs->is_syscall) {
 		if (regs->regs[4] == ERESTARTNOHAND ||
 		    regs->regs[4] == ERESTARTSYS ||
 		    regs->regs[4] == ERESTARTNOINTR) {
 			regs->regs[4] = regs->orig_r4;
 			regs->regs[7] = regs->orig_r7;
 			regs->cp0_epc -= 8;
 		}

 		if (regs->regs[4] == ERESTART_RESTARTBLOCK) {
 			regs->regs[27] = __NR_restart_syscall;
 			regs->regs[4] = regs->orig_r4;
 			regs->regs[7] = regs->orig_r7;
 			regs->cp0_epc -= 8;
 		}

 		regs->is_syscall = 0;	/* Don't deal with this again.  */
 	}

 	/*
 	 * If there's no signal to deliver, we just put the saved sigmask
 	 * back
 	 */
 	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 		clear_thread_flag(TIF_RESTORE_SIGMASK);
 		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 	}
 }

 /*
  * notification of userspace execution resumption
  * - triggered by the TIF_WORK_MASK flags
  */
 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 				__u32 thread_info_flags)
 {
 	/* deal with pending signal delivery */
 	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 		do_signal(regs);
 }
	/*
	* arch/score/kernel/signal.c
	*
	* Score Processor version.
	*
	* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
	* Chen Liqin <liqin.chen@sunplusct.com>
	* Lennox Wu <lennox.wu@sunplusct.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see the file COPYING, or write
	* to the Free Software Foundation, Inc.,
	* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#include <linux/errno.h>
	#include <linux/signal.h>
	#include <linux/unistd.h>
	#include <linux/uaccess.h>

	#include <asm/syscalls.h>
	#include <asm/ucontext.h>

	#include <asm/cacheflush.h>

	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))

	struct rt_sigframe {
	u32 rs_ass[4]; /* argument save space */
	u32 rs_code[2]; /* signal trampoline */
	struct siginfo rs_info;
	struct ucontext rs_uc;
	};

	static int setup_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	{
	int err = 0;
	unsigned long reg;

	reg = regs->cp0_epc; err \|= __put_user(reg, &sc->sc_pc);
	err \|= __put_user(regs->cp0_psr, &sc->sc_psr);
	err \|= __put_user(regs->cp0_condition, &sc->sc_condition);


	#define save_gp_reg(i) { \
	reg = regs->regs[i]; \
	err \|= __put_user(reg, &sc->sc_regs[i]); \
	} while (0)
	save_gp_reg(0); save_gp_reg(1); save_gp_reg(2);
	save_gp_reg(3); save_gp_reg(4); save_gp_reg(5);
	save_gp_reg(6); save_gp_reg(7); save_gp_reg(8);
	save_gp_reg(9); save_gp_reg(10); save_gp_reg(11);
	save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
	save_gp_reg(15); save_gp_reg(16); save_gp_reg(17);
	save_gp_reg(18); save_gp_reg(19); save_gp_reg(20);
	save_gp_reg(21); save_gp_reg(22); save_gp_reg(23);
	save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
	save_gp_reg(27); save_gp_reg(28); save_gp_reg(29);
	#undef save_gp_reg

	reg = regs->ceh; err \|= __put_user(reg, &sc->sc_mdceh);
	reg = regs->cel; err \|= __put_user(reg, &sc->sc_mdcel);
	err \|= __put_user(regs->cp0_ecr, &sc->sc_ecr);
	err \|= __put_user(regs->cp0_ema, &sc->sc_ema);

	return err;
	}

	static int restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	{
	int err = 0;
	u32 reg;

	err \|= __get_user(regs->cp0_epc, &sc->sc_pc);
	err \|= __get_user(regs->cp0_condition, &sc->sc_condition);

	err \|= __get_user(reg, &sc->sc_mdceh);
	regs->ceh = (int) reg;
	err \|= __get_user(reg, &sc->sc_mdcel);
	regs->cel = (int) reg;

	err \|= __get_user(reg, &sc->sc_psr);
	regs->cp0_psr = (int) reg;
	err \|= __get_user(reg, &sc->sc_ecr);
	regs->cp0_ecr = (int) reg;
	err \|= __get_user(reg, &sc->sc_ema);
	regs->cp0_ema = (int) reg;

	#define restore_gp_reg(i) do { \
	err \|= __get_user(reg, &sc->sc_regs[i]); \
	regs->regs[i] = reg; \
	} while (0)
	restore_gp_reg(0); restore_gp_reg(1); restore_gp_reg(2);
	restore_gp_reg(3); restore_gp_reg(4); restore_gp_reg(5);
	restore_gp_reg(6); restore_gp_reg(7); restore_gp_reg(8);
	restore_gp_reg(9); restore_gp_reg(10); restore_gp_reg(11);
	restore_gp_reg(12); restore_gp_reg(13); restore_gp_reg(14);
	restore_gp_reg(15); restore_gp_reg(16); restore_gp_reg(17);
	restore_gp_reg(18); restore_gp_reg(19); restore_gp_reg(20);
	restore_gp_reg(21); restore_gp_reg(22); restore_gp_reg(23);
	restore_gp_reg(24); restore_gp_reg(25); restore_gp_reg(26);
	restore_gp_reg(27); restore_gp_reg(28); restore_gp_reg(29);
	#undef restore_gp_reg

	return err;
	}

	/*
	* Determine which stack to use..
	*/
	static void __user get_sigframe(struct k_sigaction ka,
	struct pt_regs *regs, size_t frame_size)
	{
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->regs[0];
	sp -= 32;

	/* This is the X/Open sanctioned signal stack switching. */
	if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp)))
	sp = current->sas_ss_sp + current->sas_ss_size;

	return (void __user*)((sp - frame_size) & ~7);
	}

	asmlinkage long
	score_sigaltstack(struct pt_regs *regs)
	{
	const stack_t __user uss = (const stack_t __user ) regs->regs[4];
	stack_t __user uoss = (stack_t __user ) regs->regs[5];
	unsigned long usp = regs->regs[0];

	return do_sigaltstack(uss, uoss, usp);
	}

	asmlinkage long
	score_rt_sigreturn(struct pt_regs *regs)
	{
	struct rt_sigframe __user *frame;
	sigset_t set;
	stack_t st;
	int sig;

	frame = (struct rt_sigframe __user *) regs->regs[0];
	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	goto badframe;
	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
	goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
	if (sig < 0)
	goto badframe;
	else if (sig)
	force_sig(sig, current);

	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
	goto badframe;

	/* It is more difficult to avoid calling this function than to
	call it and ignore errors. */
	do_sigaltstack((stack_t __user *)&st, NULL, regs->regs[0]);

	__asm__ __volatile__(
	"mv\tr0, %0\n\t"
	"la\tr8, syscall_exit\n\t"
	"br\tr8\n\t"
	: : "r" (regs) : "r8");

	badframe:
	force_sig(SIGSEGV, current);

	return 0;
	}

	static int setup_rt_frame(struct k_sigaction ka, struct pt_regs regs,
	int signr, sigset_t set, siginfo_t info)
	{
	struct rt_sigframe __user *frame;
	int err = 0;

	frame = get_sigframe(ka, regs, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	goto give_sigsegv;

	/*
	* Set up the return code ...
	*
	* li v0, __NR_rt_sigreturn
	* syscall
	*/
	err \|= __put_user(0x87788000 + __NR_rt_sigreturn*2,
	frame->rs_code + 0);
	err \|= __put_user(0x80008002, frame->rs_code + 1);
	flush_cache_sigtramp((unsigned long) frame->rs_code);

	err \|= copy_siginfo_to_user(&frame->rs_info, info);
	err \|= __put_user(0, &frame->rs_uc.uc_flags);
	err \|= __put_user(0, &frame->rs_uc.uc_link);
	err \|= __put_user((void __user *)current->sas_ss_sp,
	&frame->rs_uc.uc_stack.ss_sp);
	err \|= __put_user(sas_ss_flags(regs->regs[0]),
	&frame->rs_uc.uc_stack.ss_flags);
	err \|= __put_user(current->sas_ss_size,
	&frame->rs_uc.uc_stack.ss_size);
	err \|= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
	err \|= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));

	if (err)
	goto give_sigsegv;

	regs->regs[0] = (unsigned long) frame;
	regs->regs[3] = (unsigned long) frame->rs_code;
	regs->regs[4] = signr;
	regs->regs[5] = (unsigned long) &frame->rs_info;
	regs->regs[6] = (unsigned long) &frame->rs_uc;
	regs->regs[29] = (unsigned long) ka->sa.sa_handler;
	regs->cp0_epc = (unsigned long) ka->sa.sa_handler;

	return 0;

	give_sigsegv:
	if (signr == SIGSEGV)
	ka->sa.sa_handler = SIG_DFL;
	force_sig(SIGSEGV, current);
	return -EFAULT;
	}

	static int handle_signal(unsigned long sig, siginfo_t *info,
	struct k_sigaction ka, sigset_t oldset, struct pt_regs *regs)
	{
	int ret;

	if (regs->is_syscall) {
	switch (regs->regs[4]) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
	regs->regs[4] = EINTR;
	break;
	case ERESTARTSYS:
	if (!(ka->sa.sa_flags & SA_RESTART)) {
	regs->regs[4] = EINTR;
	break;
	}
	case ERESTARTNOINTR:
	regs->regs[4] = regs->orig_r4;
	regs->regs[7] = regs->orig_r7;
	regs->cp0_epc -= 8;
	}

	regs->is_syscall = 0;
	}

	/*
	* Set up the stack frame
	*/
	ret = setup_rt_frame(ka, regs, sig, oldset, info);

	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NODEFER))
	sigaddset(&current->blocked, sig);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	return ret;
	}

	static void do_signal(struct pt_regs *regs)
	{
	struct k_sigaction ka;
	sigset_t *oldset;
	siginfo_t info;
	int signr;

	/*
	* We want the common case to go fast, which is why we may in certain
	* cases get here from kernel mode. Just return without doing anything
	* if so.
	*/
	if (!user_mode(regs))
	return;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	oldset = &current->saved_sigmask;
	else
	oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
	/* Actually deliver the signal. */
	if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
	/*
	* A signal was successfully delivered; the saved
	* sigmask will have been stored in the signal frame,
	* and will be restored by sigreturn, so we can simply
	* clear the TIF_RESTORE_SIGMASK flag.
	*/
	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	clear_thread_flag(TIF_RESTORE_SIGMASK);
	}

	return;
	}

	if (regs->is_syscall) {
	if (regs->regs[4] == ERESTARTNOHAND \|\|
	regs->regs[4] == ERESTARTSYS \|\|
	regs->regs[4] == ERESTARTNOINTR) {
	regs->regs[4] = regs->orig_r4;
	regs->regs[7] = regs->orig_r7;
	regs->cp0_epc -= 8;
	}

	if (regs->regs[4] == ERESTART_RESTARTBLOCK) {
	regs->regs[27] = __NR_restart_syscall;
	regs->regs[4] = regs->orig_r4;
	regs->regs[7] = regs->orig_r7;
	regs->cp0_epc -= 8;
	}

	regs->is_syscall = 0; /* Don't deal with this again. */
	}

	/*
	* If there's no signal to deliver, we just put the saved sigmask
	* back
	*/
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	clear_thread_flag(TIF_RESTORE_SIGMASK);
	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}
	}

	/*
	* notification of userspace execution resumption
	* - triggered by the TIF_WORK_MASK flags
	*/
	asmlinkage void do_notify_resume(struct pt_regs regs, void unused,
	__u32 thread_info_flags)
	{
	/* deal with pending signal delivery */
	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
	do_signal(regs);
	}